Schools in the Washington region spend wildly different amounts on students per pupil, and districts vary a lot in how much extra they spend on low-income students. While more spending doesn’t guarantee better quality, the discrepancies raise basic questions of fairness.

Screenshot from Metro DC School Spending Explorer. Click for interactive version.

An interactive map from the Thomas B. Fordham Institute, an education policy think tank based in DC, allows you to find the per-pupil spending amount for any school inside the Beltway. This is the first time spending data for the area has been presented on a school-by-school basis, according to Michael Petrilli, president of the institute.

That’s because individual schools within districts don’t have their own budgets, Petrilli said on the Kojo Nnamdi Show Thursday. Districts allocate staff and resources to schools depending on factors like the number of students at each school and their needs.

The data is based on expenditures during the 2011-12 fiscal year. It includes both public and private funds, but not spending on capital projects like buildings.

A data summary that accompanies the map shows that average per pupil expenditures in the area range from about $10,000 in Prince George’s County to close to $16,000 in DC Public Schools and Alexandria. DC public charter schools spend an average of just over $18,000 per student, the highest in the region.

Spending on low-income students

In a blog post analyzing the data, Petrilli and Matt Richmond focused on which District-area school systems spend the most on low-income students. Arlington County leads the pack, and Prince George’s brings up the rear, they found.

Arlington spends over 80% extra on its low-income students, or about $21,000 compared to the $12,000 it spends on its more affluent ones. But Prince George’s, which has many more low-income students, spends only about 2% more on them, or a little over $10,000.

DCPS falls somewhere in the middle for the region, spending about 21% extra on low-income students, although its spending floor is the highest of any school district in the region. (The “extra spending” figures are for elementary school students only.)

In the blog post, Petrilli and Richmond single out Montgomery County for particular scorn. Despite Superintendent Joshua Starr’s claim to be a warrior for social justice, they say, Montgomery ranks third in the region for extra spending on low-income students. At about 32%, it’s below both Arlington County and Fairfax County, which spends about 34% extra.

Low spending in Prince George’s County

But, as Petrilli and Richmond point out, the big story here is Prince George’s County’s low level of spending on its low-income population. They point out that at one Prince George’s elementary school, the amount spent per student is about half what DCPS spends at a school less than seven miles away.

Given the relatively low property tax base in Prince George’s, Petrilli and Richmond argue that the state of Maryland should be doing more to fund schools there.

Of course, it’s not clear what any of this means for educational quality. As the Fordham authors acknowledge, it’s hard to establish a direct relationship between spending and educational outcomes. More money doesn’t make much difference unless schools know what to do with it.

But it’s also true that programs designed to close the achievement gap cost money. So while money may not be sufficient to accomplish that goal, it’s almost certainly necessary.

And, as a recent report from the DC Fiscal Policy Institute details, low-income students need a host of services outside the classroom in order to succeed inside it. All of those cost money, too.

It would be useful to put school districts’ differing rates of expenditure next to a comparison of student achievement. Are low-income students in Prince George’s actually learning less than low-income students in DC or Arlington, for example?

That’s hard to say right now, because each state gives its own standardized tests, and they’re not really comparable. And the nationwide standardized test, the National Assessment of Educational Progress, basically gives results at the state-wide level rather than by school district.

Perhaps after this year we’ll at least be able to compare DC and Prince George’s County, because both Maryland and DC will be giving the same Common Core-aligned test, known as PARCC. (Virginia will continue giving its own test.)

But whatever the test results show, one thing is clear: It’s not fair for a low-income student in Arlington to get the benefit of $21,000 a year in school spending, while one across the river in Prince George’s gets half that or less.